The present invention relates to medical devices, and more particularly, to a guard for a syringe that will protect the health care professional from inadvertently sticking himself or herself with the needle after administering medication or drawing blood with the syringe.
Accidental needle puncture frequently occurs when a nurse or physician attempts to recap a needle after giving an injection or drawing blood from a patient. Needlestick injuries may transmit such infectious particles as hepatitis B virus, non-A and non-B hepatitis virus, and human immunodeficiency virus (HIV), with disastrous consequences.
U.S. Pat. No. 2,571,653 of Bastein discloses a cylindrical sheath that surrounds the syringe barrel and extends and retracts relative thereto. The needle can extend through a hole in the distal end of the sheath. The tip of the needle is recessed into the end of the sheath when the same is fully retracted. A latch on the inner surface seats in an annular groove in the sheath to lock the sheath in its fully extended position.
U.S. Pat. No. 4,425,120 of Sampson et al. discloses a cylindrical needle guard which surrounds the barrel of the syringe and moves to an extended position to shield the tip of the needle. Locking of the guard is accomplished by a track on the internal surface of the guard and track engaging members on the barrel.
U.S. Pat. No. 4,356,822 of Winstead-Hall discloses a cylindrical cap member that surrounds and reciprocates longitudinally along the barrel of a syringe. A frangible end closure is provided on the end of the cap member closest to the tip of the needle. A series of formations on the barrel engage a series of formations on the cap to permit the cap to be secured at different longitudinal positions relative to the barrel to thereby expose varying amounts of the needle.
U.S. Pat. No. 4,573,976 of Sampson et al. discloses another releasably retained, longitudinally extensible cylindrical guard that surrounds the barrel of a syringe.
U.S. Pat. No. 4,631,057 of Mitchell discloses a cylindrical needle guard that surrounds and reciprocates along the barrel of a syringe. Locking of the needle guard is accomplished by interlocking between the guard and a collar mounted on the syringe barrel.
U.S. Pat. No. 4,655,751 of Harbaugh discloses another cylindrical extensible needle guard that surrounds the barrel of a syringe. Spaced ears on the inner surface of the guard engage similar spaced ears on the outer surface of the syringe barrel to temporarily lock the guard in selected longitudinal positions.
U.S. Pat. No. 4,664,654 of Strauss discloses a needle guard having a fixed cylindrical base member mounted over the forward end of the syringe barrel and a movable cylindrical guard member which telescopes from the base member about the needle. A manually moved knob extends from the guard member through a longitudinally extending slot in the base member. A coil spring inside the base member urges the guard member to its fully extended position in which the tip of the needle is enclosed and shielded.
U.S. Pat. No. 4,681,567 of Masters et al. discloses an open-ended cylindrical safety sheath that surrounds the barrel of a syringe and is longitudinally extensible with respect to the barrel. The sheath has an elongated slot formed therein.
U S. Pat. No. 4,702,738 of Spencer discloses yet another longitudinally reciprocating cylindrical sheath that surrounds the barrel of a syringe. Substantially axial guide channels are provided in the exterior of the barrel of the syringe and accept an inwardly projecting boss of the sheath to guide the same.
U.S. Pat. No. 4,7002,739 of Milorad discloses a combination holder and extensible sleeve for surrounding and enclosing a syringe and needle. The device is primarily intended as a guide facilitating insertion of the needle into the body part.
The aforementioned devices have not been successful in the medical field because they are unduly complex, require modifications to the basic syringe, are too expensive, or do not reliably prevent emergence of tip of the needle.